Recovery of microorganisms on fabric materials after low water temperature washing with non-oxidizing acidic bleaching formulation by culture method.

The recovery of microorganisms to different fabrics was evaluated after a washing process combined with a food-grade non-oxidizing acidic formulation and low washing water temperature. Cotton, polyester and a polyester/cotton blend fabric samples were inoculated with Escherichia coli, Listeria innocua and Saccharomyces cerevisiae, then dried for 1 day. They were separately placed in a simulated fabric washer and decontaminated for 1 and 10 min with the acidic formulation at 23 °C water washing temperature. The combination of direct detecting and dilution methods was used to detect survivors on fabrics. The use of ≥ 0.1% acidic formulation in the washing process significantly increased the efficacy of the washing for all fabric samples. Microorganisms on the cotton and mixed fabric appeared to bind more strongly and were more resistant to the washing process. No viability was observed on the fabric swatches at 1 cfu/sample detection limit when the washing process was combined with 0.5% acidic formulation in the 10 min washing cycle. These findings can be used to increase the efficiency of sanitizing fabrics in an environmentally friendly way, for remove harmful microorganisms from them and reduce cross-contamination.